Abstract: The present invention generally relates to a direactive compound which is of the formula IV A R1—(CH2)mO—MG—O—(CH2)n—R2  (IVA) wherein R1, R2, m, n, and MG are defined herein.

Abstract: The invention relativ to an electroptical system

Abstract: The invention relates to a process of preparing a multilayer cholesteric film comprising two or more layers of polymerized cholesteric liquid crystal (CLC) material with planar orientation, with the cholesteric helix axis oriented substantially perpendicular to the plane of the layer, wherein that the cholesteric helical pitch of adjacent layers is varied by controlled migration of a non-polymerized chiral material between the layers, to a multilayer cholesteric film obtainable by such a process, and to the use of the process and a multilayer cholesteric film thereby prepared in optical elements such as polarizers, compensators, alignment layers, color filters or holographic elements, in cosmetics and liquid crystal pigments, for decorative and security applications.

Abstract: The invention relates to a process of preparing a multilayer cholesteric film comprising two or more layers of polymerized cholesteric liquid crystal (CLC) material with planar orientation, with the cholesteric helix axis oriented substantially perpendicular to the plane of the layer, wherein during preparation of the single layers the migration of unpolymerized material between adjacent layers is minimized, to a multilayer cholesteric film obtainable by such a process, and to the use of the process and a multilayer cholesteric film thereby prepared in optical elements such as polarizers, compensators, alignment layers, color filters or holographic elements, in cosmetics and liquid crystal pigments, for decorative and security applications.

Abstract: The invention relates to polymer beads comprising an anisotropic polymer material with helically twisted structure, to their use in reflective films, spraying or printing inks or as pigments, for optical or electrooptical, decorative or security applications, to a reflective film comprising one or more polymer beads in a transmissive binder, and to a security marking or security device comprising one or more polymer beads or comprising a reflective film.

Abstract: The invention relates to reactive liquid crystal compounds of Formula (I), wherein P=polymerizable group, Sp=spacer, X and Z=linking group, n=1, m=0, or 1, A1 and A2=ring structure and R=unsubstituted or substituted alkyl group with the proviso that m=1 and/or R—P—Sp—X group. The composition comprising reactive liquid crystal compounds of formula (I), to linear or cross-linked (co) polymers obtainable by (co) polymerizing said reactive liquid crystals or compositions and to the use of said reactive liquid crystals or compositions for the preparation of linear or cross-linked polymers or polymer films for decorative pigments, cosmetics or security applications, active and passive optical elements, color filters, scattering displays, adhesives or synthetic resins with anisotropic mechanical properties.

Abstract: 1,4-disubstituted 2,6-difluorobenzene compound of formula I wherein R is an alkyl or alkenyl radical, A1 and A2 are independently (a) a trans-1,4-cyclohexylene radical in which a CH2 group may be replaced by -O- and/or -S, (b) a 1,4-phenylene radical in which a CH group may be replaced by N, (c) 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, Z1 and Z2 are —CO—O—, —O—CO—, —CH2O—,—OCH2—, —CH2CH2—, —CH═CH—,—C≡C—or a single bond m and n are 0, 1, 2 or 3, (m+n) is 1, 2 or 3, X is R or F, Cl, CF3, —OCF3, or —OCHF2, —OCF5, —CN or —NCS with the provisos that at least one of the radicals A1 and A2 present in the molecule is  and at least one of Z1 or Z2 is —COO—, are suitable as components of liquid-

Abstract: To improve switching times, especially at low temperatures, one or more reactive liquid crystalline compounds is added to a liquid crystal mixture used in an electroptical system.

Abstract: The invention relates to a polymeric film composed of an optically anisotropic material made from a cross-linked synthetic resin composition comprising a polymer network, being obtainable by copolymerization of a mixture comprising (a) at least one monomer or oligomer, each of said monomers or oligomers having at least two polymerizable functional groups selected from the group consisting of (meth-)acrylate ester, epoxy and vinyl ether, (b) at least one achiral liquid crystalline monomer or oligomer, each of said monomersloligomers having mesogenic groups and one polymerizable functional group selected from the group consisting of (meth-)acrylate ester, epoxy and vinyl ether.

Abstract: A liquid crystal display device containing a liquid crystal cell and at least one reflective polarizer or a polarizer combination having at least one reflective polarizer as a means to generate circular polarized light. The reflective polarizer includes an optically active layer of an anisotropic polymer material with a helically twisted planar molecular orientation. The material is oriented so that the axis of the molecular helix extends transversely to the layer, and the pitch of the molecular helix is varied in such a manner that the difference between the maximum pitch and the minimum pitch is at least 100 nm.

Abstract: 1,4-disubstituted 2,6-difluorobenzene compound of formula I wherein R is an alkyl or alkenyl radical, A1 and A2, in each case independently of one another, are (a) a trans-1,4-cyclohexylene radical in which a CH2 group may be replaced by —O— and/or —S, (b) a 1,4-phenylene radical in which a CH group may be replaced by N, (c) 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, Z1 and Z2 are —CO—O—, —O—CO—, —CH2—O—, —OCH2—, —CH2CH2—, —CH═CH—, —C≡C— or a single bond m and n are 0, 1, 2 or 3, (m+n) is 1, 2 or 3, X is R or F, Cl, CF3, —OCF3, or —OCHF2, —OCF5, —CN or —NCS with the proviso that at least one of the radicals A1 and A2 present in the molecule is are suitable as components of liquid-c

Abstract: An electroptical system which between 2 electrode layers contains a PDLC film comprising a liquid crystal mixture forming micro-droplets in an optically isotropic, transparent polymer matrix, in which one of the refractive indices of the liquid crystal mixture is matched to the refractive index of the polymer matrix, which exhibits an electrically switchable transparency essentially independent of the polarization of the incident light, the precursor of the PDLC film of which comprises one or more monomers, oligomers and/or prepolymers and a photoinitiator, and is cured photoradically, the liquid crystal mixture of which comprises one or more compounds of the formula I in which the substituents are defined herein characterized in that the liquid crystal mixture additionally contains one or more reactive liquid crystalline compounds in order to obtain improved switching times especially at low temperatures.

Abstract: The invention relates to a polymeric film composed of an optically anisotropic material made from a cross-linked synthetic resin composition comprising a polymer network, being obtainable by copolymerization of a mixture comprising(a) at least one monomer or oligomer, each of said monomers or oligomers having at least two polymerizable functional groups selected from the group consisting of (meth-)acrylate ester, epoxy and vinyl ether,(b) at least one achiral liquid crystalline monomer or oligomer, each of said monomers/oligomers having mesogenic groups and one polymerizable functional group selected from the group consisting of (meth-)acrylate ester, epoxy and vinyl ether.

Abstract: The invention relates to direactive mesogenic compounds or mixtures thereof comprising mesogene-containing molecules, said mesogens having two side chains attached thereto which contain a terminal polymerizable functional group, said mesogens and said functional groups being separated by spacer groups having at least two to twenty spacer atoms, wherein both spacer groups have different chain length.

Abstract: The invention relates to an electroptical system which, between 2 electrode layers, contains a PDLC film comprising a liquid crystal mixture forming micro-droplets in an optically isotropic, transparent polymer matrix. The liquid crystal mixture comprises one or more compounds of the formula I ##STR1## wherein Z.sup.1, Z.sup.2, ##STR2## X.sup.1, X.sup.2, Q, Y, n and R are as defined herein. The liquid crystal mixture additionally contains one or more reactive liquid crystalline compounds in order to obtain improved switching times especially at low temperatures.

Abstract: The invention relates to copolymers made from mono-reactive liquid and/or di-reactive liquid crystals which can be photopolymerized to form copolymers and to novel reactive liquid crystal compound having a nematic phase. Preferentially the reactive liquid crystal is polymerized while in the liquid crystal phase to produce an oriented birefringent polymer film. To do this, the reactive liquid crystal, in its nematic or smectic phase is aligned (by well known techniques such as rubbed polyimide, etc.) and the thin film containing a small amount of photoinitiator, is subjected to ultraviolet light whereupon it polymerizes into a thin, aligned polymer film.

Abstract: A method for the loading and alignment of liquid crystal polymers in electro-optic and electro-active devices by in-situ polymerization between substrates of liquid crystal monomers. The molecular weight of the resulting liquid crystal polymer is controlled by the addition of a chain transfer reagent, for example, a thiol-containing compound which may be a liquid crystal material.

Abstract: Naphthalene derivatives of the fomula I ##STR1## in which: R.sup.1 is an alkyl or alkenyl radical which is unsubstituted, monosubstituted by CH or CF.sub.3 or monosubstituted by halogen and has 1 to 15 carbon atoms, it also being possible for one or more CH.sub.2 groups in these radicals to be replaced, in each case independently of one another, by --O--, --S--, ##STR2## --CO--, --CO--O--, --O--CO-- or --O--CO--O-- in such a manner that oxygen atoms are not linked directly to one another, ##STR3## m is 0, 1 or 2, n is 0 or 1, wherem+n is 1 or 2,Z.sup.1 and Z.sup.2 are each, independently of one another, --CH.sub.2 CH.sub.2 --, --C.tbd.C-- or a single bond,L.sup.1 and L.sup.2 independently of one another, are H or F,x is an alkyl or alkoxy radical which is unsubstituted, monosubstituted by CN or CF.sub.3 or substituted bi halogen and has 1 to 15 carbon atoms, or is OH, CN, SCN, OCN, NCS or Q--Y,whereQ is a single bond, (CF.sub.2).sub.r or O(CF.sub.2).sub.

Abstract: An electrooptical system is disclosed in which a PDLC film is positioned between 2 electrode layers. The PDLC film contains a liquid crystal mixture forming microdroplets in an optically isotropic, transparent polymer matrix. The liquid crystal mixture comprises one or more compounds of formula I ##STR1## wherein R, A.sup.1, A.sup.2, Z.sup.1, Z.sup.2, X.sup.1, X.sup.2, Q, Y and n as herein defined, and one or more reactive liquid crystalline compounds. The PDLC film exhibits improved switching times, especially at low temperatures.

Abstract: The invention relates to an anisotropic polymer film or polymer net-work obtainable by photopolymerization of at least one mesogene-containing compound, having two side chains attached to a mesogenic core structure one of which is polymerizable, the other of which is capable of forming association dimers by hydrogen bonds.